Avian bordetellosis has been identified in almost every area of the world where turkeys are intensively reared. Studies suggest that among domesticated turkeys in the Eastern U.S., about 50% are exposed to the bacterium throughout their lifetime. This disease is a highly infectious, acute upper respiratory tract infection of turkeys characterized by high morbidity and usually low mortality. The disease is usually of sudden onset within the flock and morbidity may reach 100% within 24 hours. Mortality varies, but is usually understood to be a disease of high morbidity and low mortality, however, mortality rates will rise if concurrent infections are present in the flock and if ventilation and environmental conditions are poor.
Historical vaccination with bacterins and a live temperature-sensitive mutant vaccine have given mixed results depending on the age of the turkey and the method of administration. Typically, less than 3 weeks old turkeys (e.g. poults) respond positively to vaccination with the live temperature-sensitive vaccine. Currently, vaccination is not widely practiced by turkey breeders, and the immunity that is passed to progeny generally comes from natural infections.
Bordetella avium is easily carried between farms. Normally, prevention includes a good biosecurity program with rigorous cleanup and disinfection after field outbreaks. Most of the commonly used disinfectants are somewhat effective.
The vaccine, known as the ART VAX®, is a live attenuated vaccination against Bordetella avium (also previously known as Alcaligenes faecalis), which is the etiological agent of turkey coryza causing significant problems for the turkey industry. The ART VAX® vaccine has been available commercially since its creation and has saved the turkey industry millions of dollars in losses. The vaccine was created by selection of temperature sensitive mutants from the wild type. These mutants were able to survive in the cooler nasal mucosa of young poults, but unable to replicate in the warmer lower respiratory tract. In recent years, the ART VAX® vaccine seems to have decreased efficacy, possibly because of the emergence of new strains of Bordetella avium in turkey populations.
Accordingly there is a need for an improved vaccine against Bordetella avium strains.